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Hi John,
Dave is correct. Speak to your certifer. The main thing with the windows is to avoid the risk of thermal discomfort from down draft and low radiant temperatures. For this reason the internal surfanpce temperature of the window should not fall below 16.4C on the design day (-10C). Whilst the 0.8 W/m2K is a good marker, and in the eyes of PHI applies to the UK, there are arguments for relaxation in the U-value if you are, broadly speaking, “south of Manchester”.
With regard to install: The position of the window within the wall (between int. and ext. surfaces) and the overlap of the insulation across the frame (where utilised) are key elements, as are the used of equivalent insulation types (cellulose, mineral wool, EPS, XPS etc). Again, firm this up with your certifier before this is set in stone.
Thanks to Nick Devlin for this link. (Some interesting scientific papers on basement design.)
http://www.ibp.fraunhofer.de/en/Publications/contributions_to_conferences.html#tabpanel-2
28 August 2013 at 8:58 pm in reply to: Re: Re: Local Group Leaders and Organisers Introduce Themselves #38977Hi
Mark Siddall, I'm based in Durham/Newcastle (working between the two for my own practice LEAP – the backronym for Low Energy Architectural Practice – and lecturing at Northumbria Uni). When I'm not doing those things help to I chair the North East regional group. Feel free to email me via the AECB messaging system and I'll do what I can to help.Cheers,
Mark28 August 2013 at 8:33 pm in reply to: Window installation Psi value in accordance to the PHI #38947Tom,I
What is being discussed is not “PHPP” it is a convention for calculating thermal bridges. This information may then be entered into PHPP. The main thing is that consistent and clear points of reference are used so as to avoid error.Thanks for nitpicking though. Error now ammended.
Jean-Marc,
I'm not suggesting that there is an issue free basement technology. Ideally I'd like to do is develop a way of assessing and comparing the risks so that the most appropriate solution my be sought. Believe me I'm not one for complication.19 August 2013 at 5:05 pm in reply to: Window installation Psi value in accordance to the PHI #38945I don't understand your question Tom.
Hi Peter,
Yes, I'm saying that in practice the carbon emissions will be lower with LGP.
Here is a good primer by Nick Grant and Alan Clarke: https://aecb.net/publications/biomass-a-burning-issue/
(Also check out the thread somewhere on this forum.)11 August 2013 at 7:39 am in reply to: Window installation Psi value in accordance to the PHI #38943David,
The most important thing is to be consistent in your method and to document this in such a way that another person could replicate the results. Provided that the PHPP model using the psi-values uses the same dimensional methods used in the psi-value calcs then in terms of energy calcs the results will be the same. There are differing interpretations with regard to the appropriate point at which to determine the dimensions – and you cover almost all the bases.EN standards, to which PHI refer, do not offer clarification that the level of detail that you are asking. PHPP refers to the 'rough opening' i.e. the line of structural opening for the window/door.
A) Pete Warm (Passivhaus Certifier) prefers this method as he can check dimensions against the window/door manufacturers documentation and use these dimensions in PHPP. Given that he's the certifier and I'm the designer his preference holds sway – so I use this method, however…
B) As an architect this is the option that I prefer as it is the actual structural opening and my opening schedules are based upon this dimension
C) Not appropriate as this is not the rough opening.Edited 28/08/13
Ho Ian,
May I suggest that you have a look in the building regulations:http://www.planningportal.gov.uk/buildingregulations/approveddocuments/partj/
Hi Pete,
A few thoughts:1) It sounds like the chalet MAY be used year round, but may not. Which is more likely? (This could influence the selection of appropriate heating system.)
2) I am not comfortable with using high grade energy (elec) for a low grade use (heating water/space). This is really quite inefficient/wasteful.
3) Heat losses from the electrically heated cylindar will be lost to the space (thus heating it). If the challete is not perminantly occupied (at normal household levels) then this heat will then be lost to outside with no functional use – so this becomes even more wasteful of the PV energy. If you want to manage this you will need some sort of control system – more complexity, or careful management by the owner.
4) It sounds like your carbon emissions, either by (grid) immersion or biomass, will be pretty high comapred to LPG (0.57 kg/kWh elec and about 0.45 kg/kWh biomass). Why not reinevest the capital from the wood stove into upgrading the insulation a condensing boiler and a timer/thermostat and reduce the CO2 emissions for no additional cost?
5) What airtightness target are you aiming for? Less then 3 ac/h@50pa?
6) What is the ventilation strategy?
Mark
Adam,
So join the AECB! The cost is not all that great. The benefits are great (https://aecb.net/membership-benefits/)Mark
14 July 2013 at 6:33 pm in reply to: Re: Re: PSI out of THERM – ‘floor cassette U-value’ and ‘floor modeling U-value’ #38962David
May I suggest that you go on a therm training course. Perhaps the one that is provided by the AECB Carbonlite training course. This should resolve many of the queries y are raising.ATB,
MarkP.S. I am a Carbonlite trainer (so could be viewed to have a vested interest.)
Better than therm as calcs psi-values without the need to export to excel.
I've already commented on the basic method. And confimed that you are on the right track.
….erm. There is open software available (auditable i.e. in MS Excel format) that can help you to corroborate that you are using an appropriate calculation methodology. This will help you to ensure that the degree day method that you are employing accords with BS EN standards.
Mark
What kinds of condensation analysis are you looking for? If you want the best current standards, using WUFI for example, then Joseph Little is your man. http://www.buildinglifeconsultancy.com/
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